FKIE_CVE-2026-77652

Vulnerability from fkie_nvd - Published: 2026-08-26 20:18 - Updated: 2026-08-26 20:18
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Summary
A heap-based buffer overflow vulnerability exists in the Dia diagram editor WPG file format importer. In plug-ins/wpg/wpg-import.c, the WPG import renderer allocates a fixed palette with: ren->pPal = g_new0(WPGColorRGB, 256); When handling a WPG_COLORMAP record, the parser reads a start index (i16) and number of colors (iNum16) from the file and reads palette data with: bRet &= (iNum16 == (int)fread(&ren->pPal[i16], sizeof(WPGColorRGB), iNum16, f)); The only bounds-related check is `if (i16 >= 0 && i16 <= iSize)`, where iSize is the WPG record size—not the palette capacity. There is no validation that i16 is less than 256 or that i16 + iNum16 does not exceed 256. A malicious WPG file can supply i16=256 and iNum16=264. That causes fread() to write 792 bytes starting at &pPal[256], while the palette buffer is only 768 bytes (256 entries × 3 bytes). This overflows into adjacent heap metadata and can crash Dia (SIGABRT / malloc corruption errors) or, depending on heap layout and exploit primitives, potentially lead to arbitrary code execution. Exploitation requires convincing a user to open a crafted WPG file via Dia's file dialog, command line, or file association. No special privileges are required to deliver the file to the victim. Affected component: WPG parser (plug-ins/wpg/wpg-import.c). Affected versions: all Dia versions containing this code path (reporter tested Dia 0.98+git20260221-1; issue present on upstream master as of 2026-08-21).
References
patrick@puiterwijk.orghttps://access.redhat.com/security/cve/CVE-2026-77652
patrick@puiterwijk.orghttps://bugzilla.redhat.com/show_bug.cgi?id=2520884
patrick@puiterwijk.orghttps://gitlab.gnome.org/GNOME/dia/-/blob/master/plug-ins/wpg/wpg-import.c
patrick@puiterwijk.orghttps://gitlab.gnome.org/GNOME/dia/-/issues/580
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://gitlab.gnome.org/GNOME/dia/-/issues/580",
          "defaultStatus": "unaffected",
          "packageName": "dia",
          "product": "Dia",
          "vendor": "GNOME",
          "versions": [
            {
              "lessThanOrEqual": "0.98+git20260221-1",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "patrick@puiterwijk.org"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "A heap-based buffer overflow vulnerability exists in the Dia diagram editor WPG file format importer.\n\nIn plug-ins/wpg/wpg-import.c, the WPG import renderer allocates a fixed palette with:\n\n    ren-\u003epPal = g_new0(WPGColorRGB, 256);\n\nWhen handling a WPG_COLORMAP record, the parser reads a start index (i16) and number of colors (iNum16) from the file and reads palette data with:\n\n    bRet \u0026= (iNum16 == (int)fread(\u0026ren-\u003epPal[i16], sizeof(WPGColorRGB), iNum16, f));\n\nThe only bounds-related check is `if (i16 \u003e= 0 \u0026\u0026 i16 \u003c= iSize)`, where iSize is the WPG record size\u2014not the palette capacity. There is no validation that i16 is less than 256 or that i16 + iNum16 does not exceed 256.\n\nA malicious WPG file can supply i16=256 and iNum16=264. That causes fread() to write 792 bytes starting at \u0026pPal[256], while the palette buffer is only 768 bytes (256 entries \u00d7 3 bytes). This overflows into adjacent heap metadata and can crash Dia (SIGABRT / malloc corruption errors) or, depending on heap layout and exploit primitives, potentially lead to arbitrary code execution.\n\nExploitation requires convincing a user to open a crafted WPG file via Dia\u0027s file dialog, command line, or file association. No special privileges are required to deliver the file to the victim.\n\nAffected component: WPG parser (plug-ins/wpg/wpg-import.c).\nAffected versions: all Dia versions containing this code path (reporter tested Dia 0.98+git20260221-1; issue present on upstream master as of 2026-08-21)."
    }
  ],
  "id": "CVE-2026-77652",
  "lastModified": "2026-08-26T20:18:02.160",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "patrick@puiterwijk.org",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-26T20:18:02.160",
  "references": [
    {
      "source": "patrick@puiterwijk.org",
      "url": "https://access.redhat.com/security/cve/CVE-2026-77652"
    },
    {
      "source": "patrick@puiterwijk.org",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2520884"
    },
    {
      "source": "patrick@puiterwijk.org",
      "url": "https://gitlab.gnome.org/GNOME/dia/-/blob/master/plug-ins/wpg/wpg-import.c"
    },
    {
      "source": "patrick@puiterwijk.org",
      "url": "https://gitlab.gnome.org/GNOME/dia/-/issues/580"
    }
  ],
  "sourceIdentifier": "patrick@puiterwijk.org",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-122"
        }
      ],
      "source": "patrick@puiterwijk.org",
      "type": "Secondary"
    }
  ]
}



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